Intensity-hardness correlation and deep infrared observation of the anomalous X-ray pulsar 1RXS J170849-400910

Abstract

We report here on X-ray and IR observations of the Anomalous X-ray Pulsar 1RXS J170849-400910. First, we report on new XMM-Newton, Swift-XRT and Chandra observations of this AXP, which confirm the intensity-hardness correlation observed in the long term X-ray monitoring of this source by Rea et al. (2005). These new X-ray observations show that the AXP flux is rising again, and the spectrum hardening. If the increase in the source intensity is indeed connected with the glitches and a possible bursting activity, we expect this source to enter in a bursting active phase around 2006-2007. Second, we report on deep IR observations of 1RXS J170849-400910, taken with the VLT-NACO adaptive optics, showing that there are many weak sources consistent with the AXP position. Neither star A or B, previously proposed by different authors, might yet be conclusively recognised as the IR counterpart of 1RXS J170849-400910. Third, using Monte Carlo simulations, we re-address the calculation of the significance of the absorption line found in a phase-resolved spectrum of this source by Rea et al. (2003), and interpreted as a resonant scattering cyclotron feature.

7 pages, 5 color figures; Astrophysics & Space Science, in press ("Isolated Neutron Stars"; London, UK)

References in corpus (5)

• Recent Progress on Anomalous X-ray Pulsars
• Extinction Columns and Intrinsic X-ray Spectra of the Anomalous X-ray Pulsars
• Search for radio pulsations in four Anomalous X-ray Pulsars and discovery of two new pulsars
• Swift and Chandra confirm the intensity-hardness correlation of the AXP 1RXS J170849.0-400910
• Our distorted view of magnetars: application of the Resonant Cyclotron Scattering model

Cited by in corpus (8)

• Discovery of Pulsations and a Possible Spectral Feature in the X-ray Emission from Rotating Radio Transient J1819-1458
• Detailed high-energy characteristics of AXP 1RXS J170849-400910 - Probing the magnetosphere using INTEGRAL, RXTE and XMM-Newton
• From outburst to quiescence: the decay of the transient Anomalous X-ray Pulsar XTE J1810-197
• Very deep X-ray observations of the Anomalous X-ray Pulsar 4U 0142+614
• Adaptive optics near-infrared observations of magnetars
• Linking the X-ray timing and spectral properties of the glitching AXP 1RXS J170849-400910
• Long term hard X-ray variability of the anomalous X-ray pulsar 1RXS J170849.0-400910 discovered with INTEGRAL
• VLT/NACO observations of the High-Magnetic field radio pulsar PSR J1119-6127